Flaw detector for wire mesh looms



May'26, 1953 N. w. FISHER 2,639,735

FLAW DETECTOR FOR WIRE MESH 'LOOMS Filed Feb. 13, 1950 '7 INVENTOR.

Mc ko/a s. M fisZcr AUTO/F445) Patented May 26 1953 UNITED STATES PATENT OFFICE FLAW DETECTOR FOR WIRE MESH LOOMS Nickolas W. Fisher, Cleveland, Ohio Application February 13, 1950, Serial No. 143,923

9 Claims.

This invention relates to looms and particularly to looms for weaving wire to make fine mesh or screen.

Such screens go into uses where the slightest flaw or defect cannot be tolerated even in a very large screen area, illustrative of which is the Fourdrinier screen of a paper mill.

The wire of such screens is very fine, and the screen mesh may be as fine as sixty per inch or more. The looms themselves may therefore be in general like the looms for weaving cloth from thread; but because th warp and the woof are of fine wire instead of thread, defects in the mesh tend to occur that are absent in weaving cloth, or if present are negligible.

The defects here referred to are caused by the development of small loops in the wire, which may occur due to a number of causes sometimes difficult to trace, and which loops appear at the forming edge of the screen, sometimes in a warp wire and known as creepers, at other times in a woof wire and known as kinks, and if the weaving is not stopped, these loops develop defects or flaws in the screen.

The wire weaving looms in commercial production are power driven and automatic; but it is necessary for a highly skilled attendant to keep a sharp constant watch to detect such loops and stop the loom before they are carried on into th finished mesh.

In spite of careful watchfulness, a loop will sometimes escape notice, and pass on into the finished screen, and produce a defect therein that can only be eradicated by cutting the screen apart transversely at that point. This obviously is costly because of loss of screen.

It is the primary object of the present invention to provide a detecting apparatus which will be actuated by such a loop and stop the loom automatically whereupon the loop can be quickly removed by straightening out the wire in which it formed and the loom started up again.

With this object in mind, and other objects which will occur to those skilled in the art, the invention has been made to comprise in general a metal bar or feeler disposed and supported above the woven mesh and reciprocated toward and from the weaving or forming edge of the screen known as the fell, and making electric contact with a loop whenever one develops, and thereby closing an electric circuit to actuate the stopping mechanism, generally provided on looms. The beater of the loom also reciprocates toward and from said edge or fell, and the feeler is reciprocated in synchronism with it, so that as the beater moves toward the fell the feeler retreats away from it and vice versa. Thus the feeler is moved toward the fell after each stroke of the beater and will contact and detect every loop as soon as its forms and before its proceeds into the mesh.

The actual invention is set forth in the appended claims.

The invention is fully disclosed in the following description taken in connection with the accompanying drawing, in which:

Fig. l is a top plan view with parts broken away of a part of a loom in the process of weaving wire mesh and with an embodiment of my invention applied thereto;

Fig. 2 is a side elevational view of the parts of Fig.1;

Fig. 3 is a view to greatly magnified scale of a fragment of the parts of Fig. 1 taken from the plane 3 of that figure illustrating a part of the operation of the invention when detecting a defect producing loop of one type;

Fig. 4 is a view similar to Fig. 3 wherein the defect producing loop is another type;

Fig. 5 is a view taken from the plane 5 of Fig.4;

Fig. 6 is a fragmentary view to enlarged scale taken from the plane 6 of Fig. 1;

Fig. 7 is a diagram of an electric circuit used in connection with the embodiment of the other figures.

Referring to the drawing, the following parts are shown which are common to looms and well known in the art and have therefore been shown fragmentarily and somewhat diagrammatically.

At l and 2 are heddle frames raised and lowered alternately, to repeatedly form the warp wires 3 and 4 into the shed 5. At 6 is a beater indicated as swinging from an overhead bearing, and beating the filler or woof wire 1 forwardly into the apex of the shed, to form the fell or beginning edge of the screen, sometimes called the crimp edge. The finished screen 8 moves forwardly from the fell and passes over a breast roll 9 and down therefrom to be wound on a cloth beam not shown.

The beater 6 is shown as reciprocated or oscillated by an oscillating power shaft I 0 through a long arm II on the shaft; and by a link 12 hinged to the arm H and beater B, to allow for the arcuate motions of the arm and beater. The arm I! and link I2 may be duplicated at 013-- posite sides of the beater as indicated by the fragmentary showing of both links I2 in Fig. 1.

Coming now to parts more particularly embodyin the invention, at I3 is a feeler-carrier resting by gravity upon the finished screen 8, and reciprocated thereon rearwardly toward and forwardly from the shed 5 in synchronism with the beater 6; and as the beater 6 moves toward the shed, the feeler-carrier moves away from it and vice versa.

For description purposes, the beater 6, at the level of the formed screen, may be considered as having a stroke of nine inches; and accordingly the feeler-carrier may have a stroke of three inches, although this is not essential.

The carrier it extends transversely a little more than the width of the screen 8 as shown in Fig. l; and to reciprocate the feeler with the foregoing relation to the reciprocations of the beater, and to allow for angularities of movement, and to permit the carrier to rest on the screen while reciprocating, and to keep the carrier from having a twisting or oscillating movement on the screen as it reciprocates, it is driven as follows. 7 Generally horizontal links l i-lll are pivotally connected at one end as at i555 to opposite sides of the carrier i3 near its rear end. Bell cranks iii-it mounted on a rock shaft I? are pivotally connected to the other ends of the links Ill-I l, as at 55A. Links 1% connect the bell cranks it to bell cranks 59 mounted ona rock shaft 2E1. Links 21 connect the bell cranks iii to arms I I at points 22. The arms of the bell cranks l6 and [9 may be equal; and if the links 21 are connected as shown, to the arms H at points 22 about one-third as far from the shaft Hi the links l2, the specified l-to-3 ratio of movement of the carrier It to that of the heater 5 will result; and the carrier [3 will move always in the same direction as the beater.

The bell crank and link mechanisms above described are duplicated at opposite sides of the carrier 53 for the stated purposes; as indicated by a'duplication of the links it in Fig. 1.

The bottom side of the carrier 13 is preferably in a plane as at 23 and is preferably made of hard wood, or other material softer than the wire of the screen so as not to abrade it; and preferably has electrical insulating property; and is of substantial thickness for the purpose that will appear.

' The edge of the carrier toward the shed, designated the rear ed e or face, preferably vertical and upon it is mounted a feeler 2 3 in the form of a metal bar, the lower edge of which is beveled as at 25 and at a slight distance above the planar bottom 23 of the carrier so that it will just clear the top of the screen 8, as indicated atiifi, Fig. 5. For best operative results, this distance should be uniform from end to end. of the feeler, and to this end, any suitable means may be provided to adjust it on the carrier to level it up. That shown comprises spaced brackets 2%326 on top of the carrier (Figs. 1, 2 and 5) and studs 2'!!2'l having fine threads secured to the top edge of the -feeler, and projecting upwardly through holes in the brackets; and with a nut 3'] on the stud above the bracket in each case. By turning th nut 3'! one way or the other, the stud will raise or lower the feeler with a micrometer movement. The feeler can be rely fastened in adjusted position by screws 29 (Fig. 5) projected through slots 28 in the feeler and screwed into the carrier; and if desired, look nuts 38 (Fig. 6) may be provided under the bracket 28.

For best operation, the beveled edge 25 of the feeler should be parallel with the fell or the apex of the shed '5 where the screen is being formed,

on sum that is, at the beginning edge or crimp edge and any suitable means may be provided to adjustably shift the carrier for this purpose. That shown comprises links M of turn-buckle type. Upon turning one link or the other the feeler can be squared up to be parallel with the fell. By turning both, it can be adjusted toward or from the fell; and for a fine wire mesh, it is preferably adjusted, so that on its stroke toward the fell or crimp edge, the feeler 2 3 will continue over it and overlap it, an example of the extent of overlap being one-eighth inch; although in some cases the overlap may be less or even none at all.

The said loops referred. to hereinbefore which from time to time develop and will produce defects in the screen if not eradicated are shown in Figs. 3 to 5.

In Fig. 3, a loop Ed is shown as having devel oped in a warp wire 3 and, as is usual, it stands above the level oi" the top of the screen 8.

In Figs. 4 and 5, a loop 3i is'shown as having developed in a woof or shuttle wire 1, and as usual it also stands above the level of the top of the screen 8.

When the carrier 53 is reciprocated toward the fell the metal feeler will. contact the loop 38 or 3! as the case may be, and in either case will thereby close an electric circuit as shown for the loop 3! in Fig. '7. The circuit is from a battery 32, through the winding of a magnet or solenoid to the feeler M, to loop 36 when the feeler contacts it, to ground and back to the battery.

The magnet instantly attracts a bell crank armature 3d and lifts an element 35. The element may be a shipper handle and by its movement may actuate a tripping mechanism not shown, but well known in the art to stop the loom.

The loom having thus been stopped automati cally by the loop, the wire in which the loop formed can be located and the loop eliminated by manipulating or pulling on the wire to straighten out the loop.

The said loops 3!? or 31 always develop on the upper side; and near the fell. This is due to several causes, one of which is that the beater when it beats the woof Wire into the fell is moving with an upward component of movement, due to its being hinged or pivoted at a point above the fell and between the fell and heddles. This movement sometimes also causes the fell or crimp edge thereof to be slightly higher than the top of the finished screen. In such cases, if the carrier is adjusted as described to overlap the fell, the rear edgeof the carrier may at the end of the stroke rearwardly toward the fell ride up on the crimp edge; but the beveled edge 25 of the feeler will in such cases be adjusted normally to just clear the crimp edge behind the carrier and therefore the feeler will contact on abnormal loop whether a creeper or a kink and whether such loop hasadvanced forwardly beyond the crimp edge or fell or is in such edge.

It is known that in weaving screen from wire, the fell is not always rectilinear but in some cases curves slightly convexly toward the beater. To meet this condition, the feeler M, or its edge portion .25 may be given a corresponding curvature. And herein, and in the appended claims, the description of the edge portion of the feel-er as being parallel to the fell, describes it whether the fell is rectilinear or curved.

The particular mechanism illustrated in Fig. .2 for reciprocating the beater 6 and carrier I3 con sti tutes no essential part of the invention, and

any one of a great variety of power supplying mechanisms may be used for such purpose.

Also, in the preferred embodiment of the invention, the feeler 24 is reciprocably supported reciprocatory feeler-carrier when, as illustrated,

the feeler is mounted on a feeler-carrier.

In other respects also, the construction of the parts as illustrated and described and constituting an illustrative embodiment of the invention may be changed and mo lified without departing from the spirit of the invention or sacrificing its advantages; and the invention is comprehensive of all such changes and modifications which come within the scope of the appended claims.

While the aforesaid loops are the primary danger to the fabric that is to be detected by the apparatus, it is known that, from various sources and due to various causes, detached pieces of wire or other metal sometimes fall upon the shed and are carried down to the fell and thence into the fabric causing defects therein. It has been found that these also will be detected and the loom therefore stopped by the apparatus above described; and appended claims to the apparatus are not limited to detection of loops as such and are intended to cover the apparatus when used to detect such metal pieces.

I claim:

1. In a loom of the type that weaves wire screen and advances the woven wire screen substantially horizontally forwardly from a fell, and comprises a reciprocatory beater; a feeler carrier comprising a body supported on the upper side of the woven screen; power mechanism for reciprocating it thereon rearwardly toward and forwardly away from the screen fell, in synchronism with the beater and in the same directions as the beater; a metal feeler comprising a lower edge portion on a rearward part of the carrier extending transversely of the screen; adjusting means to adjustably dispose the feeler with its edge portion in closely spaced relation to the screen, and parallel with the fell, and, at the rearward limit of motion of the carrier, rearwardly beyond the fell.

2. In a loom of the type that weaves wire screen and advances the woven wire screen substantially horizontally forwardly from a fell and comprises a reciprocatory beater; a feeler carrier comprising a body supported on the upper side of the woven screen; power mechanism for reciprocating it thereon rearwardly toward and forwardly away from the screen fell, in synchronism with the beater and in the same directions as the beater; a metal feeler comprising a lower edge portion on a rearward part of the carrier extending transversely of the screen; adjusting means to adjust the feeler on the carrier to dispose its edge portion in closely spaced relation to the screen; adjusting means to adjust the carrier relative to its reciprocating mechanism to thereby dispose the edge portion of the feeler parallel to the fell, and to dispose the edge portion rearwardly of the fell at the extreme rearward limit of reciprocating movement of the carrier.

8. In a loom of the type that weaves wire screen at a fell and has a reciprocatory beater; a metal feeler having an edge portion, extending transversely across a face of the woven screen; means supporting it in closely spaced relation thereto, and parallel to the fell; mechanism to reciprocate the edge portion away from the fell and back toward and beyond thefell, in synchronism with reciprocations of the beater.

4. In an apparatus for detecting upstanding loops in the warp or woof wires of a power driven screen weaving loom ofthe type which advances woven screen forwardly from a fell; a carrier comprising electrical insulation material and guided for reciprocatory movement by the sur-- face of the screen'forwardly of the screen fell; a metal feeler on a rearward part of the carrier comprising an edge portion extending transversely across the screen surface and spaced therefrom to be out of electric contact therewith and insulated therefrom by the insulation material of the carrier; the feeler edge portion being parallel to the screen fell; power driven mechanism connected to the carrier for reciprocating it, to thereby reciprocate the feeler edge portion away from and then toward and beyond the fell; to cause the feeler edge portion to make electrical contact with one of said loops; an electric circuit closed by said contact and comprising a source of current and an electrically actuated device; and mechanism operated by the device to stop the loom.

5'. In an apparatus for detecting upstanding loops in the warp or woof wires of a power driven screen weaving loon of the type which advances woven screen forwardly from a fell; a carrier comprising electrical insulation material and guided for reciprocatory movement by the surface of the screen forwardly of the screen fell; a metal feeler on a rearward part of the carrier comprising an edge portion extending transversely across the screen surface and spaced therefrom to be out of electric contact therewith and insulated therefrom by the insulation material of the carrier; the feeler edge portion being parallel to the screen fell; power driven mechanism connected to the carrier for reciprocating it, to thereby reciprocate the feeler edge portion away from and then toward and beyond the fell; to cause the feeler edge portion to make electrical contact with one of said loops; an electric circuit closed by said contact and comprising a source of current and an electrically actuated device; and mechanism operated by the device to stop the loom; adjusting means to adjust the said spaced distance of the feeler edge portion from the screen surface; adjusting means to adjust the parallelism of the edge portion with respect to the fell; and adjusting means to adjust the distanc beyond the fell that the edge portion reciprocates.

6. In a wire mesh weaving loom, of the type comprising a reciprocating beater that repeated- 1y beats woof wire into a crimp edge at the apex of a warp-wire shed, a metal feeler comprising an edge portion extending transversely of the woven mesh; supporting means supporting the feeler with the said edge portion adjacent to but out of contact with the woven mesh and with the edge portion parallel to the crimp edge; mechanism for reciprocating the feeler to move the said edge portion toward the crimp edge to cause it to make contact with abnormal loops in the woof-wire or warp-wire, adjacent to or in the crimp edge, and to then move the feeler away from the crimp edge, and for effecting said reciprocations of the wrap a feele'r in synchronisin'with reciprocations of the heater, to cause the feeler to be removed away from the crimp edge when the beater efiects its beating operation.

'7; In a loom of the type that weaves, Wire screen andv has a reciprocatory heater that beats woof wire into the apex of a warp wire shed to form a crimp edge; a metal ieeler having an edge portion, extending transversely across a face of the woven screen; means supporting it in closely spaced relation thereto, and parallel to the crimp edge;- mechanism to reciprocate the edge portion in synchronism with reciprocations of the beater, away from the crimp edge and back toward the crimp edge and to cause the reciprocatiorrtoward the-crimp edge to be of sufficient extent to make contact between the edge portion and an abnormal loop in the warp-wire, woof-wire, or crimp edge.

8. In an apparatus for detecting upstanding loopsin the warp or woof wires of a power driven screen weaving loom; a carrier comprising elec trioal insulation material and guided forreciproca-tory movement by the surface of the screen forwardly of the screen fell; a metal feeler on a. rearward part of the carrier comprising an edged to cause the feeleredge portion to make elec trical contact with one; of saidlloops; anelectric circuit closed. by said contact and comprising a source of current and an emergency device ac-- tuated by current in the circuit.

9. In aloom of the type that weaves wire screen and has a reciprocatory heater that beats woof wire into the apex of a Warp wire shed-=to forma crimp edge; a metal feeler having an-edgei portion, extending transversely across a face of; the woven screen; means supporting it inv closely spaced relation thereto, and parallel: to the crimp edge; mechanism to reciprocate the edge-portionin synchronism with reciprocations of the beater, away from the crimp edge and back toward the crimp edge and to cause the reciprocation toward: the crimp edge to be of sufiicient extent to-make Contact between the edge portion and an abnormal loop in the warp-wire, Woof-wire, or crimp edge, the supporting means comprising adjusting means for adjusting the. distance between the:

edge portion and the screen, and; for adjusting.

the parallelism of the edge portion and crimp, edge.

NICKOLAS W. FISHER;

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 18,320 Bigelow Oct. 6, I857 2,169,756 Buell et a]. Aug. 15', 1939 2,471,845 Szabo et a1 May 31, 1949 

